Performance analysis of a V-BLAST detector for CDMA system on the correlated multipath flat fading channel

Abstract

In recent years, Wireless communication service shows both remarkable technological advances and market growth. Young generations are more familiar with wireless internet service than voice more and more. And it caused huge growth of multimedia traffics and motivated wireless technologies to evolve its data service capacity. In order to meet with the needs of the high data transmission, higher order modulation and coding, frequency diversity and other technologies have been used. But it is relatively difficult to get more capacity with wireless transmission than wired transmission with respect to data transmission areas because wireless transmission has limited resource (frequency, space, power consumption, etc). Therefore a new release of WCDMA standard including High Speed Downlink Packet Access (HSDPA) is under development within the $3^{rd}$ generation partnership project. HSDPA is a new technology for up to 10Mbps data speed access (wireless videophone, multimedia streaming, etc) and many new technologies were introduced in HSDPA (MIMO, H-ARQ, AMC) to improve data transmission capacity. Among the new technologies, MIMO system enhances the system capacity based on transmit and receive antenna diversity scheme. It offers a significant capacity gain over a traditional single-input single-output (SISO) system. Theoretically (4,4) MIMO systems can produce four times larger capacity than (1,1) SISO system with no spectral resource increasing. So it is today regarded as one of most promising research areas of wireless communications improving capacity and spectral efficiency. But MIMO systems are greatly influenced by channel characteristics because it uses multiple channels. Multiple channels can cause high correlation of each channel from multiple array antennas and wireless paths. Its capacity on the correlated channel could be half of the capacity on the uncorrelated channel. So the technologies reducing the channel correlation are very important to achie...